1. Field of the Invention
The invention relates to a screw machine, in particular a screw compressor.
2. Description of the Related Art
The fundamental construction of screw machines designed for example as screw compressors is familiar to the person skilled in the art. Accordingly, a screw compressor comprises a machine housing or a compressor housing, which comprises a rotor housing portion and an outflow housing portion. In the rotor housing portion, screw rotors are mounted that form a rotor pair and serve for compressing a medium to compressed. Likewise, a control slide is mounted in the rotor housing portion, which in portions delimits a working space or a compression space of the rotor housing portion and for changing the size of the effective working space or effective compression space is shiftable parallel to the rotor axes of the screw rotors.
Accordingly, a screw compressor is known from DE 103 26 466 A1 with screw rotors mounted in a working space or compression space, wherein the working space is delimited in portions by a control slide, which can be shifted out of the rotor housing into the region of the outflow housing in order to define or adjust the effective working space or effective compression space. Here, the effective working space or effective compression space is the smaller the further the control slide is shifted out of the rotor housing into the outflow housing.
With screw compressors known from practice the control slide is guided in the rotor housing portion. When the effective working space of the screw compressors is to be reduced in size, the control slide is shifted out of the rotor housing portion into the outflow housing portion, wherein the effectiveness of the guide of the control slide in the rotor housing portion is dependent on the shifting path. The further the control slide is shifted into the outflow housing portion, the less the control slide is guided in the rotor housing portion. This can result in the control slide, at its end projecting into the outflow housing portion, shifting so that it collides with the screw rotors. Because of this, the screw compressor can be damaged.